As our jurisprudence under the Necessary and Proper Clause has developed, we have been very deferential to Congress’s determination that a regulation is “necessary.”We have thus upheld laws that are “‘convenient, or useful’ or ‘conducive’ to the authority’s ‘beneficial exercise.’” Comstock, 560 U. S., at _ (slip op., at 5) (quoting McCulloch, supra, at 413, 418). But we have also carried out our responsibility to declare unconstitutional those laws that undermine the structure of government established by the Constitution. Such laws, which are not “consist[ent] withthe letter and spirit of the constitution,” McCulloch, supra, at 421, are not “proper [means] for carrying into Execution” Congress’s enumerated powers. Rather, they are, “in the words of The Federalist, ‘merely acts of usurpation’ which ‘deserve to be treated as such.’” Printz v. United States, 521 U. S. 898, 924 (1997) (alterations omitted) (quoting The Federalist No. 33, at 204 (A. Hamilton)); see also New York, 505 U. S., at 177; Comstock, supra, at _ (slip op., at 5) (KENNEDY, J., concurring in judgment) (“It is of fundamental importance to consider whether essential attributes of state sovereignty are compromised by the assertion of federal power under the Necessary and Proper Clause . . .”).

Applying these principles, the individual mandate cannot be sustained under the Necessary and Proper Clause as an essential component of the insurance reforms. Each of our prior cases upholding laws under that Clause involved exercises of authority derivative of, and in service to, a granted power. For example, we have upheld provisions permitting continued confinement of those already in federal custody when they could not be safely released, Comstock, supra, at _ (slip op., at 1–2); criminalizing bribes involving organizations receiving federal funds, Sabri v. United States, 541 U. S. 600, 602, 605 (2004); and tolling state statutes of limitations while cases are pending in federal court, Jinks v. Richland County, 538 U. S. 456, 459, 462 (2003). The individual mandate, by contrast, vests Congress with the extraordinary ability to create the necessary predicate to the exercise of an enumerated power.

This is a limiting principle on the federal government. I don’t see any way around that. It’s why the four more liberal Justices disagreed in Justice Ginsburg’s opinion, and why the ruling can best be seen as a 4-1-4 split.

Many have agreed in general, but downplayed the significance and applicability of these types of conservative readings. Some legal scholars argue that the taxing power has been expanded and anything lost under the Commerce Clause can be regained as a tax. Others argue that the health care ruling was very particular and won’t have much resonance:

I’ve been pondering the future impact of yesterday’s Obamacare ruling, and I continue to think that the Commerce Clause ruling probably isn’t a big deal. After all, the activity/inactivity distinction, which John Roberts bought into, hasn’t come up in the past 200 years and probably won’t come up in the next 200 either. And if it does, Congress now has due warning that it needs to use language that doesn’t directly compel anyone to engage in commercial activity. As long as the court doesn’t extend the ruling to apply to measures that indirectly compel commercial activity, there’s just not much impact here.

(In fact, it could even be a win for liberals. Mandatory Social Security private accounts, for example, are almost certainly now unconstitutional, which just makes it easier for liberals to explain why we can’t have them. More generally, this ruling means that Congress is now on much safer ground when it simply raises taxes to fund programs directly run by the government, rather than outsourcing them to the private market. That’s friendlier to liberal ideology than to conservative ideology.)

But I think it represents a pre-Randy Barnett worldview. Barnett is the guy who invented, mostly out of whole cloth, this activity/inactivity argument. He wanted to put points on the board limiting the Commerce Clause, and he did it. There are an army of Randy Barnetts out there, all fattened up on wingnut welfare. They will be happy to offer to an inviting Court, willing to accept and respond to arguments limiting federal power and New Deal jurisprudence, novel arguments cutting down social policy and regulations. That’s a big victory.

After all, we know that four members of the Court are perfectly willing to return to the 19th century, where the government has a totally restricted role. And Roberts’ opinion lays the groundwork, inch by inch, to join the other four. We may see this play out in dozens of small rulings rather than one big one.

We already know this is a corporate court. The Chamber of Commerce didn’t lose in the Obamacare ruling (they took no position on the mandate), and they won the other case in which they intervened yesterday, giving them a still-perfect record this session. Just in the Medicaid ruling alone, we’ve seen the first limitation on Congress’ spending power in 75 years, according to UCLA School of Law professor Adam Winkler.

I don’t know if Roberts is playing a long game to upset the Constitutional order, or just creating a new one. But I know that this ruling offers a wormhole, and an army of conservative lawyers stand ready to try to exploit it. Obviously a new set of Justices would change that. So we’ll see how that plays out.